3 files changed, 67 insertions, 3 deletions
diff --git a/pkg/cli/query.go b/pkg/cli/query.go
index 0d367be..40baaec 100644
--- a/pkg/cli/query.go
+++ b/pkg/cli/query.go
@@ -28,6 +28,26 @@ import (
 	terminal "golang.org/x/crypto/ssh/terminal"
 )
 
+//Confirm displays a yes/no question and returns whether the user answered "yes".
+func Confirm(question string) bool {
+	os.Stdout.Write([]byte(strings.TrimSpace(question) + " [y/n] "))
+
+	buf := buffer{Input: os.Stdin}
+	for {
+		switch string(buf.getNextInput()) {
+		case "y", "Y":
+			os.Stdout.Write([]byte("-> yes\n"))
+			return true
+		case "n", "N":
+			os.Stdout.Write([]byte("-> no\n"))
+			return false
+		case "\x03": // Ctrl-C
+			fmt.Fprintln(os.Stderr, "\nInterrupted!")
+			os.Exit(255)
+		}
+	}
+}
+
 //Choice is a thing that the user can choose during Query().
 type Choice struct {
 	//If given, the choice can be selected by pressing the key that
@@ -89,8 +109,6 @@ OUTER:
 		case "\x03": // Ctrl-C
 			fmt.Fprintln(os.Stderr, "Interrupted!")
 			os.Exit(255)
-		default:
-			fmt.Printf("%#v\n", string(input))
 		}
 
 		//prepare to re-render choices
diff --git a/pkg/rtree/index.go b/pkg/rtree/index.go
index 2edc452..f6ee2f4 100644
--- a/pkg/rtree/index.go
+++ b/pkg/rtree/index.go
@@ -108,6 +108,17 @@ func (i *Index) Write() {
 	path := indexPath()
 	util.FatalIfError(os.MkdirAll(filepath.Dir(path), 0755))
 	util.FatalIfError(ioutil.WriteFile(path, buf, 0644))
+
+	//perform sanity check (TODO: do this instead when rebuilding the index)
+	seen := make(map[string]bool)
+	warned := make(map[string]bool)
+	for _, repo := range i.Repos {
+		if seen[repo.CheckoutPath] && !warned[repo.CheckoutPath] {
+			fmt.Fprintf(os.Stderr, "warning: repo %s appears multiple times in the index file!\n", repo.AbsolutePath())
+			warned[repo.CheckoutPath] = true
+		}
+		seen[repo.CheckoutPath] = true
+	}
 }
 
 //InteractiveRebuild implements the `rtree index` subcommand.
@@ -235,6 +246,7 @@ func (i *Index) InteractiveFindRepo(remoteURL string, allowClone bool) *Repo {
 	}
 
 	if !allowClone {
+		util.ShowError(errors.New("no such remote in index (you can validate the index with `rtree index`)"))
 		return nil
 	}
 
@@ -347,3 +359,25 @@ func (i *Index) InteractiveImportRepo(dirPath string) {
 	util.FatalIfError(repo.Move(checkoutPath, true))
 	i.Repos = append(i.Repos, &repo)
 }
+
+//InteractiveDropRepo deletes the given repo from the rtree and removes it from
+//the index.
+func (i *Index) InteractiveDropRepo(repo *Repo) {
+	ok := repo.InteractiveExec("git", "status")
+	if !ok {
+		return
+	}
+	if !cli.Confirm(">> Drop this repo?") {
+		return
+	}
+
+	util.FatalIfError(os.RemoveAll(repo.AbsolutePath()))
+
+	reposNew := make([]*Repo, 0, len(i.Repos)-1)
+	for _, r := range i.Repos {
+		if r.CheckoutPath != repo.CheckoutPath {
+			reposNew = append(reposNew, r)
+		}
+	}
+	i.Repos = reposNew
+}
diff --git a/pkg/rtree/main.go b/pkg/rtree/main.go
index 4c8fb98..683daeb 100644
--- a/pkg/rtree/main.go
+++ b/pkg/rtree/main.go
@@ -38,7 +38,10 @@ func Exec(args []string) {
 		}
 		commandGet(args[1])
 	case "drop":
-		panic("unimplemented")
+		if len(args) != 2 {
+			usageAndExit()
+		}
+		commandDrop(args[1])
 	case "index":
 		if len(args) != 1 {
 			usageAndExit()
@@ -88,6 +91,15 @@ func commandGet(url string) {
 	}
 }
 
+func commandDrop(url string) {
+	index := ReadIndex()
+	repo := index.InteractiveFindRepo(url, false)
+	if repo != nil {
+		index.InteractiveDropRepo(repo)
+		index.Write()
+	}
+}
+
 func commandIndex() {
 	index := ReadIndex()
 	util.FatalIfError(index.InteractiveRebuild())